If pointing the Wiimote at your screen like you were giving a presentation on the quarterly fiscal reports when you're playing Duck Hunt isn't quite realistic enough, then check out this Wii Light Gun attachment. It's a gun that you slip your Wiimote into, giving you the benefit of a gun grip and triggers while still making the Nunchuk port available for attachments.

Best of all, it's only $19, which means if it turns out to be horrible you won't be wasting that much money. – Jason Chen